Some of the users who adopted Eric Schmidt's face. Photograph: Google+

Google users are changing their Google+ profile pictures to photos of Eric Schmidt, the company’s executive chairman, in protest against its plan to use customer information in adverts.

From 11 November, Google will share users' recommendations and reviews with their friends, in what the company is calling “shared endorsements”.

A five star review of an album that a person leaves on the Google Play store could in future appear next to an advert for it, or a "+1" given to a restaurant could be shown next to that location’s paid result in maps.

Users can opt out of having their picture and details used by changing a setting - but the default is that people are opted in to having their data used.

But as an alternative method of protest against the changes, some users have changed their profile pictures on Google+ to that of Eric Schmidt, the company's executive chairman and former chief executive.

If you have a Google Account, we may display your Profile name, Profile photo, and actions you take on Google or on third-party applications connected to your Google Account (such as +1’s, reviews you write and comments you post) in our Services, including displaying in ads and other commercial contexts. We will respect the choices you make to limit sharing or visibility settings in your Google Account. For example, you can choose your settings so your name and photo do not appear in an ad.

Some may find that they have already opted out of the policy change. That is because Google applies the same privacy settings it had for a previous sharing option to the new one.

If a user has already opted-out of making allowing their +1s to appear in ads, then they are automatically opted out of the new shared endorsements as of 11 November.

Those users changing their profile pictures to Eric Schmidt’s face may be better off if they just opt out of shared endorsements. The company is known for enforcing a strict real-name policy, and its rules against impersonation require parodies to be “clearly labelled”.

It is not known whether Eric Schmidt has opted out of having his name and picture used in endorsements via Google+.

•To block the use of your personal views in endorsements, go to the shared endorsement settings and uncheck the box beside the text "Based upon my activity, Google may show my name and profile photo in shared endorsements that appear in ads."